Server+ Certification Exam Notes

Server+ Certification awarded by CompTIA organization is a
widely recognized certification in the area of
servertechnologies. To attain Server+ certification, one need to score at least 75%. These exams basically test the
Knowledge in the areas such as Server installation, configuration, maintenance, troubleshooting, and SANs among others.The exam consists of 80 questions
and a maximum allowable time of 90 minutes.For further details, you can visit the official website here.

3. If the termination
is not done, a SCSI devices on the bus will not function
properly. This is due to reflection of the signals at
the end of the bus. To prevent this, both ends of the
SCSI bus need to be terminated. If one end of the SCSI
bus is terminated, you may find intermittent problems.
Never terminate the bus at a device connected in
between.

4. LUN stands for
Logical Unit Number. LUN is used to identify a logical
device that is an independent functional part of a SCSI
device. SCSI-2 specification allows 8 logical units for
each SCSI device address. The logical unit addresses are
numbered 0 to 7.

b.RAID 1: Disk Mirroring
and Disk Duplexing.Disk Mirroring requires at least two partitions
of same size. Each partition should be on a different
physical drive. In other words, minimum 2 disks are
required. For disk duplexing minimum 2 disks and
2 controllers are required. RAID 1 provides good fault
tolerance, though disk access is slower compared to disk
striping.

c.RAID 2: Disk Striping
with Error correction.

d.RAID 3: Disk striping
with error correction code stored as parity

Thistakes a striped array as in RAID 0, then adds a
parity hard disk drive to the array.This parity information is vital if one drive
fails. If a drive should fail in this situation, the
parity drive can be used to restore blocks that have
been broken due to data corruption.

e.RAID 4: Disk striping
with large blocks allocation.

f.RAID 5: Disk Striping
with Parity. Disk Striping with Parity requires at least
three partitions of same size, and each partition should
be on a different physical drive. In other words,
minimum 3 disks are required for disk striping
with parity. Fault tolerant, less expensive than disk
mirroring. If more than one disk fails, data can't be
recovered. You still need to depend on tape back up for
multiple disk failures.

RAID
5 is similar to RAID 3, except the parity information is
spread across all drives, this allows all drives to be
able to rebuild the array if a drive fails. In RAID 3
parity is written to only one drive.

Note
that, compared to disk striping or disk striping with
parity; Disk mirroring has more overhead, as the entire
disk get copied to another disk.

7.
RAID 10 describes Mirrored Striping. It is a mode 0
array, plus a mode 1 array, striped. For example, if you
have striped data into two drives, each drive is
mirrored in RAID 10. That is a total of 4 drives.

2.Active: This
terminator has a voltage regulator that ensures the
correct termination voltage.

3.Forced Perfect
Termination (FPT):A better implementation of active
termination that clamps to the output of two regulated
voltages.

9.
Each device in a SCSI chain needs to have unique ID. For
a 16-bit Wide SCSI, there are 16 possible SCSI Ids,
0-15. A standard 8-bit SCSI can support only 8 devices
(including SCSI card), the Ids allowed are 0-7.

10.
RAID is implemented across several platforms: SCSI,
FIBRE-SCSI and IDE are the most common implementations
of RAID technologies.